webadmin: Fixed public profile in add/edit network

Didn't do nothing before, now actually sets whether the profile may be
used by all users or not.

Change-Id: Ie87563dd45d3343bd963c2f4a1ed228361589823
Bug-Url: https://bugzilla.redhat.com/1000801
Signed-off-by: Lior Vernia <lvernia@redhat.com>